According to sites like Android Authority, this smartphone with model name C660X currently is being tested with Android 4.1.1. However, given that the device will be launched only by early next year, chances are that it will sport Android 4.2 at the time of launch.
But does a 6 inch device really qualify as a smartphone. The current biggest phone is the 5.5 inch screen bearing Samsung Galaxy Note II. Given that the Note (first version) came with a 5.3 inch screen and was called a Phablet (Tablet+Phone), this one from Sony might be more of a tablet than a phone.
The pricing and availability details of the purported Sony Yuga smartphone are not available.
Sony apparently also has a 5 inch screen device called Odin C650X. Keep checking The Mobile Indian for more information about it.